First, let me say that this visualization, along with many in the book, is quite visually engaging. The data is interesting, and it would make a beautiful poster. That said, from an InfoVis point of view, I think there are issues with this design.

Most importantly, the rings are, due to the geometry, different sizes. This means that the slices of each annulus get progressively smaller as you move to the centre. So, the colours of western society are given more visual presence than those of South America.

The location and dual nature of the legend means that to read this graphic a lot of back and forth referencing is needed. Also, it's difficult without at least faint gridlines to determine which ring each colour block is on. This is especially true for blocks in isolation, such as the red block in radial 12.

I personally might have visualized this using a small multiples diagram -- one for each word, perhaps with a single vertical slice for each region.

It would not be as compact, but I think it would be clearer. Of course, this is just a five minute idea and I'm sure it has lots of problems too. His graphic is clearly designed as a poster, and as such, it works well and would look nicer than my idea hanging on the wall.